My personal take on this issue is that a good iPad cover can function the way you would want a screen protector to, and it much more worth the investment.
My iPad case protects my device from drops (link) and also acts as a smart cover ensuring that the screen is protected when I am not using the iPad. The guy at the Mac store even told me that many screen protectors make it so that the covers won't fit. I am pretty sure I made the right call...